Measuring instrument



P 1942- R. T. McQUEEN 2,296,531

MEASURING INSTRUMENT Filed June 3, 1940 2 Sheets-Sheet 2 I' IJHIWI zzmm wm IN V EN TOR.

I'ITIH l l l [Ill Ill]

A TTORNEYS.

Patented Sept. 22, 1942 UNITED STATES PATENT OFFICE azsam museums ms'raumm'r 1mm '1'. McQueen, Butler, Tenn. Application June a, 1940, Serial N6. 338,618

lclaim.

This invention relates to measuring instruments of the protractor type, the primary object of the invention being to provide a measuring instrument of this character, constructed in such a way that it may be capable of many uses, such as a miter gauge, tri-square, bevel Another object of the invention is to provide a measuring instrument wherein the pivoted measuring arm thereof is provided with an adjustable slide formed with an opening for the reception of a pencil, whereby circles and various arcs of circles may be accurately described.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and ar-. rangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein described, may be made within the scope of what is claimed, without departing from the spirit of the invention.

Referring to the drawings: 7

Figure 1 is a plan view of a measuring instrument constructed in accordance with the invention.

Figure 2 is an edge elevational view of the measuring instrument. I

Figure 3 is a longitudinal sectional view of the measuring instrument assembled for dwcribing circles and arcs of circles.

Figure 4 is a sectional view taken on line l-4 of Figure 1.

Figure 5 is a sectional view taken on line i--l of Figure 1.

Figure 6 is a sectional view taken on line 0-6 of Figure 1.

Figure 7 is an elevational view of one end of the removable arm, illustrating the thickness gauge as extended for measuring the thickness of a board.

Figure 8 is a sectional view taken on line H of Figure 7 Referring to the drawings in detail, the body portion of the instrument is indicated generally by the reference character I, and as shown presents a curved edge 0 and a straight edge 1, the upper surface of the body portion adjacent to the curved edgebeing graduated indicating inches and fractions of inches, as clearly shown by Figure l of the drawings.

A groove 8 is formed in the curved edge of the body portion and extends throughout the length of the curved edge, the groove being disposed intermediate the upper and lower surfaces of the body portion.

Formed integral with the body portion} and extending therefrom, are arms 9 and ill, the arms being substantially wide and formed with right angled surfaces ll providing a substantially V-shaped head for the reception of square objects to be gauged. These arms 9 and III are about one-half of the thickness of the body portion, to the end that a portion of the curved edge 6 is above the arms 9 and ill, for purposes to be hereinafter more fully described.

A pivot screw indicated at I I is secured to the body portion at a point intermediate the ends of the straight dge I, and affords means for securing the pivoted measuring arm l2 to the body portion. Mounted on the pivot screw Ii, is a bearing l3 which is formed with. an elongated extension, ll of a width to fit within the slot ii of the measuring arm i2- A screw cap I6 is mounted on the outer end of the pivot screw II p and cooperates with the bearing l3 in clamping the pivoted measuring arm I2 in position.

The pivoted measuring arm I2 is formed with a slot II that extends throughout substantially the entire length of the arm l2, the slot accommodating the slide it which is provided with a threaded stem that accommodates the nut 19. The nut I9 cooperates with the measuring arm l2 in securing the slide in various positions of adjustment throughout the length of the measuring arm. As clearly shown by the drawings the slide includes a lateral extension arm 20 formed with an opening for the reception of a pencil which describes a circle or arcs of circles, when the pivoted measuring .arm is moved with respect to the body portion, as indicated in dotted lines in Figur 1 of the drawings. At one end of the body portion 5, is a slot providing a straight wall 2| against which one edge of the measuring arm I2 is positioned, when the measuring instrument is to be used as a tri-square. As indicated in full lines in Figure 1 of the drawings, the measuring arm i2 is positioned in the slot and is held against the wall 2i, by means of the bolt 22. This bolt 22 is formed with a head 23 which is offset at the inner end of the bolt, the head being designed to fit within the slot ll. A nut 24 is mounted on the threaded i end of the bolt 22 and operates to draw the head 23 into close engagement with the measuring arm l2, securing the measuring arm against move-' 1 ment with respect to the body portion 5, to in- 1 sure accuracy in the use of the measuring instru- 1 ment, after the measuring blade has been set for 1 a predetermined measurement. 1 sired to release the measuring arm, it is only nec- 1 essary to loosen the nut 24 and rotate the bolt When it is detomove the head out of engagement with the I adjust it with respect to the body portion.

A flange indicated at 25 extends downwardly This flange It might be further stated that the slide I8 is supplied" with a wide 'finger26 that fits in the I groove 8 formedflin the curved surface of the i body portion. means forjsecuring the pivoted measuring arm i in various positions of adjustment with respect to the gradu'ation's along the curved edge of the 1 body portion, by operating the nut l9 to tighten I the nut. An indicator 2'! forms a part of the finger 26, and cooperates with the graduations j formedalong the curved edge of the bodyporj tion, sothat the pivoted measuring arm may be i accurately adjusted with respect to the graduaitions;

A slot indicated at 28 is formed in the upper surface of the measuring arm 12, and extends in- 1 wardly from one end thereof. This slot 28 ac i commodates the rule 29 which is provided with a 3 head 3,0 at one end thereof, the head 30 being of 1 a length equal to the width of the measuring arm This finger provides a locking l2, as shown byFigure 7 of the drawings. This Figure 7, of the drawings for use in measuring 3 thickness of boards.

An opening is formed in one side of the body portion, for the reception of the center pin 3| which is pointed, so that when the device is used in describing a circle, the pivot screw H may be the pin 3| may now be pressed into the surface .10 3 measuring arm. The measuring arm may then 3 be readily slid from its position, or moved to to be described. I

In order that the device may be used as a level, V

- The body portion of the measuring instrument acts as the head of the tri-square, and the arm may be adjusted to various lengths.

When the device is to be used for describing circles, the measuring arm is removed from its position as shown in full lines in Figure 1, and

graduations of the body portion, so that circles and arcs of circles may be accurately described.

What is claimed is: I

A measuring instrument comprising a body portion having a straight edge and a curved edge, the curved edge having a groove formed throughout the length thereof, a measuring arm having a slot'formed throughout substantially the entire 1 rule may be extended to a position as shown by length thereof, a pivot memberextending through.

portion and the free, end of the arm, an exten- 7 sion on the slide formed with an opening for the reception of a marking member, a finger on the slide movable in the groove in the curved surface of the body portion, means on the slidecooperating with the finger for clamping the slide and arm to 'the body portion, said means embodying a screw and nut, and said screw and nut adapted to hold theslide in various positions of adjust-' mentthroughout the'length of the arm'whereby curved lines defining the arcs of circles, may be made when the arm is pivoted with respect to the body portion. t

' ROBERT T. MCQUEEN. 

